The present invention relates to a device for self-adjusting or regulating the length of an automobile parking brake cable, in particular for private passenger cars and transport vehicles.
As is known, the purpose of the parking brake incorporated as original equipment in automobiles is to hold the vehicle immobile once it has been parked, even when it is parked on a steep slope. The parking brake generally acts on the rear wheels of the automobile and, in any case, the parking brake mechanical actuating device is independent of the service or foot brake actuating device.
The parking brake is generally actuated manually by a brake lever which is disposed in the vehicle and connected by sheathed steel cables to the mechanisms applying the brake shoes or calipers which immobilize the vehicle on each rear wheel. The said brake lever is provided with mechanical means setting the position in which the parking brake is operative, preventing the said brake lever from accidentally coming out of the braking position under normal service conditions.
The said sheathed steel cables connecting the brake lever to the brake shoe or caliper actuating mechanism of each rear wheel are subject to variations of length. This causes unequal operation of the brake device which is compensated by mechanisms acting permanently on the sheathed steel cables.
The known parking brake sheathed steel cable length compensation mechanisms suffer, nevertheless, from notable operative drawbacks when the brake shoes or calipers are temporarily seized, i.e., when the brake shoes or calipers do not return to the normal released position until some time has passed after releasing the brake lever. This situation is frequently caused by accumulation of ice on the brake shoe or caliper actuating mechanisms during extended parking of the vehicle in the open air, in regions where low temperatures are usual.